I started some Roma tomatos in Autumn in my (unheated) polytunnel. Here in
NZ we get frosts & cool temperatures through winter, nothing tomatos
outdoors like. The first fruit is now fully grown so I harvested it & placed
them in paper bags along with a ripening pear. Result is nearly mature fruit
ready to use when I want. If you can get the plants growing through autumn &
winter then ripening them in paper bags with fruit is a decent way to get
tomatos through winter.

rob